The discovery of Helicobacter pylori (H. pylori) and its role in gastric ulcers triggered a revolution in gastroenterology research (Megraud et al., Helicobacter pylori resistance to antibiotics in Europe and its relationship to antibiotic consumption. Gut. 2013; 62:34-42; Arias & Murray, Antibiotic-resistant bugs in the 21st century—a clinical super-challenge. The New England journal of medicine. 2009; 360:439-43). H. pylori is one of the most ubiquitous bacterial pathogens in humans, and it has colonized the stomachs of as many as half of the global human population. This pathogen may cause a variety of gastroduodenal diseases, including gastritis, peptic ulcer, MALT lymphoma, and gastric cancer (Fock et al., Helicobacter pylori research: historical insights and future directions. Nature reviews Gastroenterology & hepatology. 2013; 10:495-500). However, various attempts to develop preventive vaccines against H. pylori have failed. In the event that infection is diagnosed, H. pylori is treated with conventional antibiotic regimens. However, the success rate of these treatments is compromised by the drastic increase of antimicrobial resistant strains of H. pylori (Rimbara E, Fischbach L A, Graham D Y. Optimal therapy for Helicobacter pylori infections. Nature reviews Gastroenterology & hepatology. 2011; 8:79-88; Marshall B J, Warren J R. Unidentified curved bacilli in the stomach of patients with gastritis and peptic ulceration. Lancet. 1984; 1:1311-5). Many classical antibiotics are ineffective at eradicating H. pylori. The early 1990's saw the beginning of triple therapy regimens against such infection. Recently, however, emerging resistance against the most clinically-important antibiotics, metronidazole and clarithromycin, has had a major detrimental effect on the efficiency of triple therapy; furthermore, an increase in the frequency of resistant strains would limit the use of these antibiotics in future regimens, because resistance cannot be overcome by increasing the dose or duration of treatment (Fischbach L, Evans E L. Meta-analysis: the effect of antibiotic resistance status on the efficacy of triple and quadruple first-line therapies for Helicobacter pylori. Alimentary pharmacology & therapeutics. 2007; 26:343-57; Megraud F. H. pylori antibiotic resistance: prevalence, importance, and advances in testing. Gut. 2004; 53:1374-84).
It is still desirable to develop a new drug or an alternative drug regimen for treating gastric ulcers or H. pylori infections.